1. Field of The Invention
The present invention relates generally to gas burners, and more particularly, to an improved burner assembly construction for a blow torch type burner.
2. Descriptions Of The Prior Art
The application and use of gas burners in many varying fields is well known. Gas burners are required, for example, for use in applications involving boilers, internal combustion engines, and many other devices, as well as for use in applications requiring soldering and brazing of metals. In every application, however, attempts have been made to most advantageously burn a combustible gas for the particular application.
Many such attempts involve the manipulation of the flow of the combustible gas to cause ignition of the gas in a desired location or manner. For example in a radiant cell gas burner disclosed in U.S. Pat. No. 2, 070,859, a combustible gas is caused to be propelled in a spiralling pattern through the burner cell so as to repeatedly strike the ceramic side walls of the cell. Such repeated striking of the gas against the walls causes an increased proportion of the heat generated during combustion of the gas to be transformed into radiant heat.
Of particular importance to the present invention is the generation of a flame by a burner utilized for soldering and brazing metals. Frequently referred to as blow torch burners, many such burners have been developed to burn various gasses.
Different types and mixtures of combustible fuels are utilized by such burners for each specific application. For example, propane and butane are common fuel sources for low temperature welding or brazing applications, and other fuels, such as acetylene, are utilized when higher temperature flames are required in other welding applications.
One such prior art burner is disclosed in U.S. Pat. No. 4,013,395. The burner disclosed therein causes a combustible gas to evolve through a burning chamber in a spiralling fashion to create a flame at an exit end thereof suitable for brazing of metals. The flame produced by this burner, however, is short, but undersirable because of its loud noise and uneven flame, the excessive loud noise and uneven flame is caused by the helical rotation of the gases plus three large passage ways (vanes).
Use of this or other prior art burners is therefore at times disadvantageous. Far more preferable would be a use of a burner which produces a compact, quieter flame, having an even large heat zone. In the prior art, however, no such burners are known to exist.
What is needed, therefore, is a gas burner assembly apparatus which allows a combustible fuel mixture to produce a broad flame so as to allow more controllable even heating of a braze area of a metal.
This invention deals primarily with a burner that uses atmospheric air for combustion instead of oxygen. The use of atmospheric air is less expensive than oxygen, but yields suitable temperatures for heating, soldering and brazing. Oxygen, however, is necessary for cutting because of rapid oxidation needed to cut metal with acetylene, propane, butane, etc.
In prior art of atmospheric air torches it is known to mix the air with the gas in various ways but all fail to produce an optimum flame. Some burners businesses or torch tips do not have a mixing device in the flame tube to enhance mixing. Those that do have a mixing device use slugs having straight holes, straight vanes, helical holes or helical vanes in the slugs to mix the air-gas. The burner device of the present invention uses a mixing slug that has straight holes arranged to diverge outwardly toward the bluff-end in relation to the flow of gas-air. This design and relation of parts improves mixing of the gas and the atmospheric air. The flame tube walls are kept cool because of the divergent angles and the velocity of the mixture is fast, but not so fast as to lose the proper mixture.
It is therefore an object of the present invention to overcome the disadvantages associated with the prior art.
It is a further object of the present invention to provide a burner assembly which provides a flame having a uniform even heat zone to allow even heating of a braze or weld joint area of a metal that it not greatly effected by regulator changes in gas pressure, therefore it is easier to operate by the user.
It is a yet further object of the present invention to provide a burner assembly which provides a compact but quieter flame having a large heat zone when burning any of a variety of combustible gaseous mixtures.